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Analogous to electronic transistors, transistor‐like responsive materials undergo sharp structural transitions in response to a very narrow range of microenvironment signals. This kind of material is typically limited to synthetic polymer‐derived nanoscale assembly or disassembly and has profound implications for modern high‐tech applications. Herein, we evolve this system from synthetic polymers to biopolymers and extend the corresponding assembly scale from the nanoscale to meso/macro‐scale. We develop unique protein nanocrystals with core–shell structures through a two‐step nucleation process. The protein nanocrystals exhibit exceptional transistor‐like pH‐responsive mesoscale assembly through the formation of inter‐particle β‐sheet linkers. This allows ultrasensitive cross‐linking behavior, such as self‐coacervation at a water/water interface, ultrafast gelation in seconds, and ultrasensitive swelling for detection of basic vapors at extremely low concentrations. This breakthrough has great promise for broader applications such as drug encapsulation and delivery, biosensing, cytomimetic materials, and microfluidic chemistry. [ABSTRACT FROM AUTHOR]

Exploring high‐efficiency and stable halide perovskite‐based photocatalysts for the selective reduction of CO2 to methane is a challenge because of the intrinsic photo‐ and chemical instability of halide perovskites. In this study, halide perovskites (Cs3Bi2Br9 and Cs2AgBiBr6) were grown in situ in mesoporous TiO2 frameworks for an efficient CO2 reduction. Benchmarked CH4 production rates of 32.9 and 24.2 μmol g−1 h−1 with selectivities of 88.7 % and 84.2 %, were achieved, respectively, which are better than most reported halide perovskite photocatalysts. Focused ion‐beam sliced‐imaging techniques were used to directly image the hyperdispersed perovskite nanodots confined in mesopores with tunable sizes ranging from 3.8 to 9.9 nm. In situ X‐ray photoelectronic spectroscopy and Kelvin probe force microscopy showed that the built‐in electric field between the perovskite nanodots and mesoporous titania channels efficiently promoted photo‐induced charge transfer. Density functional theory calculations indicate that the high methane selectivity was attributed to the Bi‐adsorption‐mediated hydrogenation of *CO to *HCO that dominates CO desorption. [ABSTRACT FROM AUTHOR]

The article titled "Inside Cover: pH-Responsive Protein Conformation Transistor" discusses the successful creation of protein nanocrystals that exhibit rapid crystalline cross-linking behavior at pH levels above 7.6. This discovery has led to the development of a protein conformation proton transistor, which has potential applications in biomedicine, biosensing, and microfluidic chemistry. The research suggests that this pH-triggered cross-linking can be achieved in conditions similar to physiological environments, making it highly relevant to these fields. The authors of the article are Fei Tao, Qian Han, Miaoran Deng, Shuting Miao, and Peng Yang. [Extracted from the article]

Directing CO2 conversion using photosynthetic microorganisms offers a promising route to couple CO2 sequestration with petrochemical replacement. However, the low‐flux shikimate pathway remains largely unexploited for the synthesis of valuable aromatics. In addition, it is unclear how an enhanced low‐flux pathway would influence the photosynthetic chain. We created a powerful metabolic sink by introducing the 2‐phenylethanol pathway and an artificial feedback‐inhibition‐resistant cassette to Synechococcus elongatus. More than 30 % of the fixed carbon was redirected to the shikimate pathway for aromatic synthesis, and carbon fixation and O2 evolution increased significantly. A "self‐remodeling" mechanism of the photosynthetic chain was discovered, which accelerates electron transport and reduces energy waste. This study represents a significant step toward the industrial viability of CO2 conversion into aromatic compounds and provides design guidance for improving photosynthetic efficiency. Sink or swim: By introducing a powerful metabolic sink, more than 30 % of the fixed carbon from photosynthesis was directed toward the low‐flux shikimate pathway for aromatic compound synthesis. Carbon fixation and O2 evolution increased significantly, and a "self‐remodeling" mechanism for the photosynthetic chain was demonstrated. This provides a route to aromatic compounds directly from CO2, as well as guidance for improving photosynthetic efficiency. [ABSTRACT FROM AUTHOR]

Abstract: The biosynthesis of aromatic aldehydes and alcohols from renewable resources is currently receiving considerable attention because of an increase in demand, finite fossil resources, and growing environmental concerns. Here, a temperature‐directed whole‐cell catalyst was developed by using two novel enzymes from a thermophilic actinomycete. Ferulic acid, a model lignin derivative, was efficiently converted into vanillyl alcohol at a reaction temperature at 30 °C. However, when the temperature was increased to 50 °C, ferulic acid was mainly converted into vanillin with a productivity of 1.1 g L−1 h−1. This is due to the fact that the redundant endogenous alcohol dehydrogenases (ADHs) are not active at this temperature while the functional enzymes from the thermophilic strain remain active. As the biocatalyst could convert many other renewable cinnamic acid derivatives into their corresponding aromatic aldehydes/alcohols, this novel strategy may be extended to generate a vast array of valuable aldehydes or alcohols. [ABSTRACT FROM AUTHOR]